Objective: The purpose of this study was to explore whether the symptoms that patients with major depressive disorder have lower energy, which is a unique symptom can be measured by the Motivation and Energy Inventory (MEI). Method: We recruited 22 outpatients with major depressive disorder. We assessed them with the Hamilton Depression Rating Scale (HAM-D), the Taiwanese Depression Questionnaire (TDQ), World Health Organization Quality of Life (WHO-QoL) and the Motivation and Energy Inventory (MEI). Results: The results showed that the MEI sub scores, except the social motivation subscale, are highly correlated with all domains of the depression scales. Conclusion: The sum of state of energetic motivation measured by the MEI might be not a unique symptom in patients with major depressive disorder. But the symptoms related to social motivation needs more attention in clinics.